Stereotaxy device



W. T. HEYER STEREOTAXY DEVICE Jan. 23, 1962 Filed Jan. 19, 1960 IN VEN TOR. WILL/4M 7T HEYIFR A TTOR/VEYJ.

United States Patent 3,017,887 STEREOTAXY DEVICE William T. Heyer, 411 N. Wilson Ave., Pasadena, Calif. Filed Jan. 19, 1960, Ser. No. 3,446 4 Claims. (Cl. 128-348) This invention relates to a stereo-taxy device.

That the more distressing symptoms of Parkinsonism and other hyperkinetic disorders may be relieved surgically has now gained general acceptance. A common means for relieving these symptoms is by creating destructive lesions in the brain which are localized by a stereotaxy method. The lesions are made by drilling a small cranial opening, attaching a stereotaxy device in. said opening, guiding a needle or catheter with the device to the site within the brain where the destructive lesion is to be formed, and then introducing material for creating said lesions, such as an alcohol paste, through the catheter to the selected location. The purpose of the stereotaxy device is to provide guiding means for the needle or catheter so that the needle or catheter goes to the correct location (requiring proper direction and depth control) on the first penetration.

In hitherto known stereotactic devices, it has been necessary to attach the device in a cranial opening, such as by tapped threads, and then to leave the device in place on the persons head for three or four days, because the destructive paste is introduced only a little at a time, and always in doses that are less than the total amount ultimately needed, so that too much of the brain will not be destroyed. This takes several days to do, and the needle or catheter must be left in place. The necessity for carrying a large device around simply in order to keep a small catheter in place is a discomfort to the patient which ought to be avoided, if possible. However, previously-known devices could not be removed from around the device they guided into place, so the inconvenience and discomfort have had to be tolerated.

It is an object of this invention to provide a light, convenient to-use and accurate stereotaxy device which can be removed from the cranial opening after it serves its function, leaving the catheter in place in the brain.

A stereotaxy device according to the invention includes a base that carries a clamp, whereby the base may be attached to the skull. Offset from the clamp and overhanging the cranial opening when the clamp is installed therein, there is provided an opening including a ball seat, and threads to receive a retainer. A swivel member has a ball on the end thereof adapted to be placed between the retainer and the ball seat, so the swivel member can be held in any adjusted angular position. The swivel member, the base, and the retainer all have a slit in their sides. It is a feature of this invention that all of these axial slits can be simultaneously aligned so that a catheter or needle can be removed from the device and remain in place when the device is removed from the cranial opening.

The above and other features of this invention will be fully understood from the following detailed description and the accompanying drawings, in which:

FIG. 1 is a side elevation, partly in cutaway cross-section, showing the presently preferred embodiment of the invention;

FIG. 2 is a right-hand view of the device in FIG. 1;

FIG. 3 is a top view of FIG. 1;

FIG. 4 is another right-hand view of the device of FIG. 1 with the parts in a different position; and

FIG. 5 shows the device in use on the head of a human being.

In FIG. 1, there is shown a stereotaxy device 9 which includes a base 10. Clamping means are provided for holding the base to a human skull, the clamping means including a flange 11 integral with the bottom of the base carrying a laterally projecting lip 12, and a threaded screw 13 with a point 14 thereon. The screw is engaged in and passes through a threaded hole 15 in the base. A slot 16 is provided in the end of the screw to receive a torque-applying tool such as a screwdriver to tighten down the clamp. As best shown in FIG. 5, the base is attachable to the skull over an opening 17 therethrough by sliding lip 12 beneath the skull and tightening the screw down so that the point embeds itself in the skull, thereby holding the base in a fixed position.

Near the other end of the base, there is an opening 18 therethrough, which opening includes a ball seat 19 located axially between a cylindrical section 20 and a threaded section 21. A slit 22 through the base into the opening extends from end to end of the opening. A retainer 23 has exterior grooves 24 for engagement by a torque-type tool, such as a wrench, at its upper end, and exterior threads 25 adapted to thread into threaded section 21. The retainer has a passage therethrough which includes a ball seat 26 at its lower end and adjacent thereto, a flaring conical opening 27 at the upper surface, and an axial slit 28 through its side, extending from end to end of the retainer. A swivel member 29 includes a balllike member 30 at its end, which ball-like member is suitably sized so that it may be brought down against ball seat 19, and can be held in any adjusted position by tightening down on the retainer. The swivel member also includes an opensided channel member 31 which is integral with the ball-like member. The swivel member has a slit 32 extending from end to end thereof, which extends the entire length of the channel member as well as of the ball-like member.

As a reference for aligning the swivel member in space, a protractor device 33 is provided. The protractor is a bent rod which can be plugged into a socket 34 in the upper end of screw 13. The rod is round and so is the socket, so that the protractor device may be turned to lie in any selected plane. The upper end of the protractor device has a curved portion 34 with notches 35 therein to serve as calibrated angular references. It is necessary to check the angular position of the swivel member in a plurality of planes to determine its location in space. The protractor provides for this requirement by being rotatable in the socket.

The use of this device is shown in FIG. 5. The ultimate objective is to introduce a catheter 40 into some selected region of the human brain, and then inject fluid, such as an alcohol paste, through the catheter in an amount suificient to create a lesion of the brain at that location. Thereby, it is hoped to relieve paralysis or paroxysms caused by disorders in that portion of the brain. The catheter is introduced through the hole in the cranium by passing it through the channel member and base. It is reinforced by a steel rod inside it which is removed after the catheter is positioned in the brain. While the catheter is being held and guided, the retainer and swivel members are turned so that their slots are not both simultaneously aligned with the slot in the base. Then there is always some portion of the device which holds the catheter in. In order to adjust the swivel member to the desired angle so that the catheter will be in troduced in the correct direction, the retainer is loosened so that the swivel member can move around in its full potential universal movement.

When it is believed that the device is correctly positioned, X-rays are taken along two axes, and the location which would be assumed by the catheter if guided by the swivel member, is calculated on the plates. When the X-rays are taken, the protractor device will be in place with the arcuate portion parallel to the plane of the film, so that the notches will give a reference showing the location of the swivel member when the picture is taken, and the angle through which it must be moved to reach correct alignment. If adjustment is necessary, the retainer is released, the swivel member is moved the correct amount, the retainer is tightened again, and new X-rays are taken. Because the protractor device can swivel around its axis, this simple bent wire is all that is needed for angular reference, regardless of the plane in which the position of the channel member is being checked.

A catheter to be installed is of a size to fit snugly in the swivel member, so that the swivel member acts as a guide to direct the catheters entry into the brain. It is reinforced by a rod at this time. The rod will be later withdrawn before the catheter is used to convey fluid to the brain.

It is an advantage of this invention that the device can be removed from the skull after the catheter is installed, without disturbing the catheter. This is desirable, because the catheter will be used for three or four days while small amounts of solution are injected into the brain, and it is uncomfortable and disagreeable for a patient to have to wear the device all this time, as has hitherto been necessary. To remove the device and leave the catheter behind, the retainer is backed off to release the ball-like member enough so it can turn around its own axis. Then the swivel member and the retainer member are turned so that their slits are aligned with the slots in the base. Next, the clamping means are released, and then the device may simply be removed by sliding the catheter out through the aligned slits while the lip of the clamp is removed from the inside of the skull. FIG. 2 shows the slits of the base, swivel member, and retainer in nonaligned array. A catheter therein would be captive. FIG. 4 shows the slits aligned. A catheter could be removed.

This invention thus provides an extremely simple, easy to handle, and accurately alignable stereotaxy instrument. It provides means whereby the instrument may be removed while permitting the catheter installed with its use to remain undisturbed in the skull.

This invention is not to be limited by the embodiment shown in the drawings and described in the description, which is given by way of example and not of limitation, but only in accordance with the scope of the appended claims.

I claim:

1. A stereotaxy device comprising: a base having an opening therethrough and a slot through the side of said base extending for the full length of the opening; a ball seat in said opening; clamping means on the base for attaching it to a skull at an opening therein; threaded means on said base; a retainer having a passage therethrough and a slot through the side of the retainer extending for the full length of the passage; a ball seat in the retainer; threaded meanson said retainer engageable with the base, whereby with the retainer threaded onto the base, the ball seats may be brought toward each other; and a swivel member comprising a ball-like portion adapted to be placed between the ball seats so as to be swivelly movable therein and to be held in an adjusted position by tightening said threaded means together, said swivel member including a channel portion integral with and extending away from said ball-like portion and passing through the passage in the retainer, said swivel member having an open slot along its entire length, whereby the retainer, base, and swivel member may be so rotationally riented in a first condition with respect to one another that the slots are not all simultaneously aligned, and whereby there is a second condition of their rotational orientation wherein they are all aligned, whereby with the base installed over an opening in a human skull, the swivel member may be placed in some desired geometrical orientation and retained there by tightening the retainers ball seat against the ball-like member, and whereby with the retainer, base, and swivel member in said first condition, a catheter passed through the swivel member into the skull is retained and guided by the stereotaxy device, and with them in said second condition, the stereotaxy device is removable from the skull, still leaving the catheter in place in the head.

2. Apparatus according to claim 1 in which the clamping means include a flange having a laterally extending finger, and a screw threadedly engaged in and passing through the base directed toward said finger, whereby said screw may be advanced toward said finger so as to clamp a portion of the human skull therebetween.

3. A device according to claim 2 in which the screw includes a point on one end thereof, and means for receiving a torque-applying device on the other end thereof.

4. A device according to claim 2 in which said screw is provided with a socket, and in which a protractor device is provided adapted to be rotatably held in said socket, said protractor including an angularly calibrated portion.

References Cited in the file of this patent UNITED STATES PATENTS Flagg May 21, 1918 Nauth May 7, 1940 

